Adhesive composition and process of making same.



Ill

WALTER ALEXANDER, 01F YORK, N. Y.', ASSIGNOR 'I'O NATIONAL GUM & MICA CUIIIPANY, 01: NEW YORK, N. IL, A CORPOEATIUII OF NEW YORK.

To all whom it may concern:

Be it known that I, WALTER ALEXANDER, a citizen of the United States, and a resident of the borough of Manhattan, in the city, county, and State of New York, have invented and discovered a new and useful Improvement in Adhesive Compositions and Processes of Making Same, of which the following is a specification.

My invention relates to a method of treatment of the several species of gums termed generally gum acacia or gum arabic, or the like water-soluble natural gums, by the addition thereto of a small percentage of a boron derivative.

It has for its object the production of a dry product which is markedly waterabsorptive, and whose penetrating, spreading, and adhesive properties are notably increased and strengthened.

It has for its further objects the production of a berated dry gum of the arabic species, suitable as a substitute for animal glue, gelatin, aqueous dextrin, modified or soluble starches, as artificial gum or British gum, and soluble adhesives generally, and which composition may be termed a supergum, in that it has the capacity for ready incorporation with other substances and compounds, whether neutral, acid, or alkaline in reaction, permitting its employment Ali advantageously as a universal binder even where chemical or physical conditions are present which would otherwise normally antagonize or repel these water-soluble gums.

In carrying out my invention, preferably I treat the commercial gum arabic to free it from foreign impurities by dissolving it and filtering the solution. In the case of gums containing volatile constituents or oils therewith, I drive oil the non-essential ingredientsby boiling. In either case I reduce the residual clear gum to a dry state and then preferably grind it to a granular or powdered form. To this pulverized gum I add a small percentage of a suitable boron compound in like form. The mixture is thor-' oughly agitated until a homogeneous distribution is attained. Instead of the dry process described and preferred, I may first dissolve the gum in water, add the boron compound to the solution, and then evaporate the water therefrom. The boron-treated Specification ct Letters Patent.

Patented Apr 223, ram.

Application filed February 8, 1917. Serial No. M1330.

gum resultant will be found to possess waterab'sorbing properties in high degree and to attain the otherdesired objects previously stated As' specific examples of my invention as applied to gum arabic, two formulae are recited:

I. Take 110 pounds of gum, arabic dissolved in 390 pounds of water. Add to this solution four pounds of commercial borax.

Agitate this mixture, preferable with low heat, until a complete solution is attained, and then evaporate the water therefrom.

II. Granulate 110 pounds of In arabic. With this powdered gum mix It? pounds of commercial borax, likewise in powdered or granular form.

The arabic, an acid gum, will stifien up wit out neutralizin the alkalinity of the boron compound. I, on the contrary, the borax be neutralized as to its alkalinity by suitable acid, the gum arabic will nevertheless'stifi'en up. Similarly, if the acidity of the gum arabic has been first neutralized, the berated gum arabic will stifi en up as in the other cases. If, however, the acidity of the gum. arabic or other like acid gum first be neutralized, certain oils and greases may be combined therewith, and the mixture may be emulsified. 'Ihe super-gum, as I have termed it, of my discovery is apparently both a physical and chemical compound, and is characterized by its absorptive quality, having a high afiinity for water.

Among the useful applications of these improved gums are their superior advantages as stififeners, sizings, binders, and dressings for straw and straw hats; as a size and finish for fabrics; as a preservative coating, and as an adhesive adaptedto general combining uses.

Having thus described the best method known to me for making, compounding, and using my inventions or discoveries, both as to processes and products, and without limiting my claims thereto save as the essential steps recited are involved in the production of a berated gum, I claim:

1. As a new article, dry berated gum.

2. As a new article, dry borated gum arabic.

3. As a new article, finely divided dry berated gum arabic.

I. The process of producing a dry com- All position consistin in dissolving a soluble boron compound therewith, and driving off gum of the arable species and mixin a the water from the solution. water-soluble boron compound therewlth, 6. The process of producin compositions 10 and evaporating the product. of the class described consistlng in dissolv- 5. The process of producing compositions ing gum arabic, mixing borax therewith, of the class described consisting in dissolvand drying the mixture. ing gum arabic, dissolving a water-soluble WALTER ALEXANDER- 

